Landscape intactness has been defined as a quantifiable estimate of naturalness measured on a gradient of anthropogenic influence. We developed a multiscale index of landscape intactness for the Bureau of Land Management’s (BLM) landscape approach, which requires multiple scales of information to quantify the cumulative effects of land use. The multiscale index of landscape intactness represents a gradient of anthropogenic influence as represented by development levels at two analysis scales.

To create the index, we first mapped the surface disturbance footprint of development, for the western U.S., by compiling and combining spatial data for urban development, agriculture, energy and minerals, and transportation for 17 states. All linear features and points were buffered to create a surface disturbance footprint. Buffered footprints and polygonal data were rasterized at 15-meter (m), aggregated to 30-m, and then combined with the existing 30-meter inputs for urban development and cultivated croplands. The footprint area was represented as a proportion of the cell and was summed using a raster calculator. To reduce processing time, the 30-m disturbance footprint was aggregated to 90-m. The 90-m resolution surface disturbance footprint is retained as a separate raster data sets in this data release (Surface Disturbance Footprint from Development for the Western United States). We used a circular moving window to create a terrestrial development index for two scales of analysis, 2.5-kilometer (km) and 20-km, by calculating the percent of the surface disturbance footprint at each scale. The terrestrial development index at both the 2.5-km (Terrestrial Development Index for the Western United States: 2.5-km moving window) and 20-km (Terrestrial Development Index for the Western United States: 20-km moving window) were retained as separate raster data sets in this data release. The terrestrial development indexes at two analysis scales were ranked and combined to create the multiscale index of landscape intactness (retained as Landscape Intactness Index for the Western United States) in this data release. To identify intact areas, we focused on terrestrial development index scores less than or equal to 3 percent, which represented relatively low levels of development on multiple-use lands managed by the BLM and other land management agencies.

The multiscale index of landscape intactness was designed to be flexible, transparent, defensible, and applicable across multiple spatial scales, ecological boundaries, and jurisdictions. To foster transparency and facilitate interpretation, the multiscale index of landscape intactness data release retains four component data sets to enable users to interpret the multiscale index of landscape intactness: the surface disturbance footprint, the terrestrial development index summarized at two scales (2.5-km and 20-km circular moving windows), and the overall landscape intactness index. The multiscale index is a proposed core indicator to quantify landscape integrity for the BLM Assessment, Inventory, and Monitoring program and is intended to be used in conjunction with additional regional- or local-level information not available at national levels (such as invasive species occurrence) necessary to evaluate ecological integrity for the BLM landscape approach.

Mid- to very large-sized Douglas-fir (Pseudotsuga menzieseii var. menziesii) that were lightly- to moderately-infected by dwarf mistletoe (Arceuthobium douglasii) were analyzed over a 14-year period to evaluate whether mechanical pruning could eradicate mistletoe (or at least delay the onset of severe infection) without significantly affecting tree vitality and by inference, longevity. Immediate and longterm pruning effects on mistletoe infection severity were assessed by comparing pruned trees (n = 173) to unpruned trees (n = 55) with respect to: (1) percentage of trees with no visible infections 14 years post-pruning, (2) Broom Volume Rating (BVR), and (3) rate of BVR increase 14 years postpruning. Vitality/longevity (compared with unpruned trees) was assessed using six indicators: (1) tree survival, (2) the development of severe infections, (3) the development of dead tops, (4) tree-ring width indices, (5) Normalized Difference Vegetation Index (NDVI) from high-resolution multi-spectral imagery, and (6) live-crown ratio (LCR) and increment. Twenty-four percent of the pruned trees remained free of mistletoe 14 years post-pruning. Pruning is most likely to successfully eradicate mistletoe in lightly infected trees (BVR 1 or 2) without infected neighbors. Pruning significantly decreased mean BVR in the pruned versus the unpruned trees. However, the subsequent average rate of intensification (1.3–1.5 BVR per decade) was not affected, implying that a single pruning provides ~14 years respite in the progression of infection levels. Post-pruning infection intensification was slower on dominant and co-dominants than on intermediate or suppressed trees. The success of mistletoe eradication via pruning and need for follow-up pruning should be evaluated no sooner than 14 years after pruning to allow for the development of detectable brooms. Based on six indicators, foliage from witches brooms contribute little to long-term tree vitality since removal appears to have little effect on resources available for tree growth and maintenance. In the severely pruned trees, tree-ring width was reduced for several years post-pruning, but then compensated with larger ring width in later years. Both NDVI and LCR increment were significantly higher for the pruned trees than the control trees, while the development of severe infections and/or dead tops was significantly (5X and 3X) higher for the controls. If possible, multiple indicators of tree vitality should be evaluated. Pruning can be worthwhile even if all the mistletoe is not removed, because mistletoe intensification is delayed. The impact of removing the brooms seems to be minimal, and post-pruning crowns had greater NDVI values.

Federal investments in ecosystem restoration projects protect Federal trusts, ensure public health and safety, and preserve and enhance essential ecosystem services. These investments also generate business activity and create jobs. It is important for restoration practitioners to be able to quantify the economic impacts of individual restoration projects in order to communicate the contribution of these activities to local and national stakeholders. This report provides a detailed description of the methods used to estimate economic impacts of case study projects and also provides suggestions, lessons learned, and trade-offs between potential analysis methods.

This analysis estimates the economic impacts of a wide variety of ecosystem restoration projects associated with U.S. Department of the Interior (DOI) lands and programs. Specifically, the report provides estimated economic impacts for 21 DOI restoration projects associated with Natural Resource Damage Assessment and Restoration cases and Bureau of Land Management lands. The study indicates that ecosystem restoration projects provide meaningful economic contributions to local economies and to broader regional and national economies, and, based on the case studies, we estimate that between 13 and 32 job-years4 and between $2.2 and $3.4 million in total economic output5 are contributed to the U.S. economy for every $1 million invested in ecosystem restoration. These results highlight the magnitude and variability in the economic impacts associated with ecosystem restoration projects and demonstrate how investments in ecosystem restoration support jobs and livelihoods, small businesses, and rural economies. In addition to providing improved information on the economic impacts of restoration, the case studies included with this report highlight DOI restoration efforts and tell personalized stories about each project and the communities that are positively affected by restoration activities. Individual case studies are provided in appendix 1 of this report and are available from an online database at https://www.fort.usgs.gov/economic-impacts-restoration.

Publication Title:

The differing biogeochemical and microbial signatures of glaciers and rock glaciers

Glaciers and rock glaciers supply water and bioavailable nutrients to headwater mountain lakes and streams across all regions of the American West. Here we present a comparative study of the metal, nutrient, and microbial characteristics of glacial and rock glacial influence on headwater ecosystems in three mountain ranges of the contiguous U.S.: The Cascade Mountains, Rocky Mountains, and Sierra Nevada. Several meltwater characteristics (water temperature, conductivity, pH, heavy metals, nutrients, complexity of dissolved organic matter (DOM), and bacterial richness and diversity) differed significantly between glacier and rock glacier meltwaters, while other characteristics (Ca2+, Fe3+, SiO2 concentrations, reactive nitrogen, and microbial processing of DOM) showed distinct trends between mountain ranges regardless of meltwater source. Some characteristics were affected both by glacier type and mountain range (e.g. temperature, ammonium (NH4+) and nitrate (NO3- ) concentrations, bacterial diversity). Due to the ubiquity of rock glaciers and the accelerating loss of the low latitude glaciers our results point to the important and changing influence that these frozen features place on headwater ecosystems.

The U.S. Geological Survey issued a joint press release with the Oregon Zoo on April 20, 2016 featuring results of a new study using zoo polar bears to help scientists better understand the effects of the polar bear's changing diet in remote Arctic regions.

Examining Current Subspecies Delineations in White-tailed Ptarmigan Using Genomic Data

The delineation of populations that are evolutionarily and demographically distinct is an important step in the development of species-specific management plans. Such knowledge is necessary for learning how conservation threats vary across a species’ range, for devising strategies to increase population growth rates, and for providing legal protection at the intraspecific level. It is also essential for conserving long-term evolutionary resilience, given that the genetic diversity that has evolved in response to spatial variation in environmental conditions could provide the raw ingredients necessary to fuel future adaptive evolution. We are using genomic data to delineate distinct evolutionary units across the range of the white-tailed ptarmigan. This information will inform management strategies for this alpine species, which may be vulnerable to climate change.

Publication Title:

Unsupported inferences of high-severity fire in historical dry forests of the western United States: response to Williams and Baker

Reconstructions of dry western US forests in the late 19th century in Arizona, Colorado and Oregon based on General Land Office records were used by Williams & Baker (2012; Global Ecology and Biogeography, 21, 1042–1052; hereafter W&B) to infer past fire regimes with substantial moderate and high-severity burning. The authors concluded that present-day large, high-severity fires are not distinguishable from historical patterns. We present evidence of important errors in their study. First, the use of tree size distributions to reconstruct past fire severity and extent is not supported by empirical age–size relationships nor by studies that directly quantified disturbance history in these forests. Second, the fire severity classification of W&B is qualitatively different from most modern classification schemes, and is based on different types of data, leading to an inappropriate comparison. Third, we note that while W&B asserted ‘surprising’ heterogeneity in their reconstructions of stand density and species composition, their data are not substantially different from many previous studies which reached very different conclusions about subsequent forest and fire behaviour changes. Contrary to the conclusions of W&B, the preponderance of scientific evidence indicates that conservation of dry forest ecosystems in the western United States and their ecological, social and economic value is not consistent with a present-day disturbance regime of large, high-severity fires, especially under changing climate.

Publication Title:

Influence of nonnative and native ungulate biomass and seasonal precipitation on vegetation production in a great basin ecosystem

The negative effects of equid grazers in semiarid ecosystems of the American West have been considered disproportionate to the influence of native ungulates in these systems because of equids’ large body size, hoof shape, and short history on the landscape relative to native ungulates. Tools that can analyze the degree of influence of various ungulate herbivores in an ecosystem and separate effects of ungulates from effects of other variables (climate, anthropomorphic disturbances) can be useful to managers in determining the location of nonnative herbivore impacts and assessing the effect of management actions targeted at different ungulate populations. We used remotely sensed data to determine the influence of native and nonnative ungulates and climate on vegetation productivity at wildlife refuges in Oregon and Nevada. Our findings indicate that ungulate biomass density, particularly equid biomass density, and precipitation in winter and spring had the greatest influence on normalized difference vegetation index (NDVI) values. Our results concur with those of other researchers, who found that drought exacerbated the impacts of ungulate herbivores in arid systems.

Dam removal is often proposed for restoration of anadromous salmonid populations, which are in serious decline in California. However, the benefits of dam removal vary due to differences in affected populations and potential for environmental impacts. Here, we develop an assessment method to examine the relationship between dam removal and salmonid conservation, focusing on dams that act as complete migration barriers. Specifically, we (1) review the effects of dams on anadromous salmonids, (2) describe factors specific to dam removal in California, (3) propose a method to evaluate dam removal effects on salmonids, (4) apply this method to evaluate 24 dams, and (5) discuss potential effects of removing four dams on the Klamath River. Our flexible rating system can rapidly assess the likely effects of dam removal, as a first step in the prioritization of multiple dam removals. We rated eight dams proposed for removal and compared them with another 16 dams, which are not candidates for removal. Twelve of the 24 dams evaluated had scores that indicated at least a moderate benefit to salmonids following removal. In particular, scores indicated that removal of the four dams on the Klamath River is warranted for salmonid conservation. Ultimately, all dams will be abandoned, removed, or rebuilt even if the timespan is hundreds of years. Thus, periodic evaluation of the environmental benefits of dam removal is needed using criteria such as those presented in this paper.

Publication Title:

Environmental contaminants and biomarker responses in fish from the Columbia River and its tributaries: Spatial and temporal trends